Maternal protein intake affects offspring's facial features

The protein content of the diet during pregnancy can affect the face of the offspring, according to research led by the University of Gothenburg. This has been shown in animal studies, and the underlying mechanism was also found in human genetic studies.

A child is expected to share facial features with their parents; however, the face is also influenced by environmental factors such as the mother’s lifestyle during pregnancy (for example, extensive alcohol consumption during pregnancy can lead to facial abnormalities in the child). Now, an international research team has delved into the mechanisms that control the formation of the facial bone structure during the embryonic phase, revealing that a particular signalling pathway in the cells seems to play a crucial role in shaping the face.

The signalling pathway, known as mTOR, controls several cell functions, including cell division and cell survival, and is known to be the target of an immunosuppressive medicinal product, rapamycin, which is administered during organ transplantation to avoid rejection. The signalling pathway also acts as an intracellular nutritional sensor specifically tailored to amino acids, the building blocks of proteins.

Having found that the mTOR pathway modulates the formation of facial skeletal structures in humans, mice and zebrafish, researchers sought to investigate whether the protein content of the pregnancy diet affects mTOR and plays a role in the formation of the facial bone structure. Their results were published in the journal Nature Communications.

Pregnant mice were given diets with high and low protein levels. As the researchers expected, the protein levels in the female’s diet were consistent with the activity level of mTOR in the developing face. In newborn offspring, the differences in the face were noticeable, albeit subtle.

“It is difficult to describe the exact effects which can be caused by protein content in the diet during human pregnancy,” said research leader Professor Andrei Chagin. “But our data suggest that the mechanism is evolutionarily conserved and, from this perspective, likely serves to increase variability in the feeding apparatus, thus allowing animals to adapt to various feeding sources in the wild. In mice we see, for example, an enlarged nasal cavity in the offspring of mice fed a protein-enriched diet and a slightly elongated jaw in mice where the mother has eaten a low-protein diet.”

The aim of the international study — which included researchers from Sweden, Austria, Belgium, China, the Czech Republic, Japan and Russia — was to contribute to the future development of more effective clinical methods for the prevention and treatment of different types of facial congenital malformations and to increase knowledge of what a good pregnancy diet should contain. According to Chagin, “The findings emphasise the importance of maintaining a well-balanced diet during pregnancy, with particular attention to protein intake … [and] open insights open new avenues for understanding the intricate interplay between genetics, lifestyle and the formation of our unique facial features.”

Image credit: iStock.com/Marco VDM